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A 'passivated precursor' approach is developed for the efficient synthesis and isolation of all‐alkynyl‐protected gold nanoclusters. Direct reduction of dpa‐passivated precursor Au‐dpa (Hdpa=2,2'‐dipyridylamine) in one‐pot under ambient conditions gives a series of clusters including Au22(C≡CR)18 (R=−C6H4−2−F), Au36(C≡CR)24, Au44(C≡CR)28, Au130(C≡CR)50, and Au144(C≡CR)60. These clusters can be well separated via column chromatography. The overall isolation yield of this series of clusters is 40 % (based on gold), which is much improved in comparison with previous approaches. It is notable that the molecular structure of the giant cluster Au130(C≡CR)50 is revealed, which presents important information for understanding the structure of the mysterious Au130 nanoclusters. Theoretical calculations indicated Au130(C≡CR)50 has a smaller HOMO‐LUMO gap than Au130(S−C6H4−4−CH3)50. This facile and reliable synthetic approach will greatly accelerate further studies on all‐alkynyl‐protected gold nanoclusters. [ABSTRACT FROM AUTHOR]

The application of supramolecular templates in aligning atomically precise heterometal arrays is important for pursuing functional materials. Herein, we report that a bilayered supramolecular tri‐deprotonated melamine dimer functions as an effective template in the construction of a heterometallic gold(I)‐silver(I) macrocyclic cluster [μ6‐(C3N6H3)3−]2−AuI6AgI6. X‐ray single crystal structural analysis showed that a crown‐like AuI6AgI6 macrocycle is aligned around two parallelly stacked μ6‐(C3N6H3)3− moieties hold together with π–π interactions. Theoretical calculations revealed that the [μ6‐(C3N6H3)3−]2 motif dominantly contributes to the near‐occupied orbitals in the electronic structure, which is closely related to its luminescence properties. This work demonstrates that the supramolecular templates containing multiple symmetric binding sites may present a facile approach in the construction of functional metal clusters. [ABSTRACT FROM AUTHOR]

Anions have been used to regulate the structures and luminescence of heterometallic clusters. Introducing ClO4− into orange‐emissive, butterfly‐like [(C)(Au‐PPhpy2)6Ag4](BF4)6 (1, PPhpy2=bis(2‐pyridyl)phenylphosphine) leads to the formation of red‐emissive [(C)(Au‐PPhpy2)6Ag5(ClO4)3](ClO4)4 (2) with a novel trigonal bipyramidal structure; employing PhCO2− gives yellow‐emissive, hexagram‐like [(C)(Au‐PPhpy2)6Ag6(PhCO2)3](BF4)5 (3). Notably, 1 exhibits weak luminescence in CH2Cl2/CH3OH=1 : 1 (v : v) with a quantum yield (QY) of 0.05, whereas it was dramatically increased to 0.49 and 0.83 for 2 and 3, respectively. Theoretical calculation confirms that the involvement of anions in the electronic structures is responsible for the shifts of emission. The high QYs of 2 and 3 are attributed to the protection provided by ligands and anions. This work demonstrates that anions may serve as an extra designable factor beyond just counterions for functional metal clusters. [ABSTRACT FROM AUTHOR]

A 'passivated precursor' approach is developed for the efficient synthesis and isolation of all‐alkynyl‐protected gold nanoclusters. Direct reduction of dpa‐passivated precursor Au‐dpa (Hdpa=2,2'‐dipyridylamine) in one‐pot under ambient conditions gives a series of clusters including Au22(C≡CR)18 (R=−C6H4−2−F), Au36(C≡CR)24, Au44(C≡CR)28, Au130(C≡CR)50, and Au144(C≡CR)60. These clusters can be well separated via column chromatography. The overall isolation yield of this series of clusters is 40 % (based on gold), which is much improved in comparison with previous approaches. It is notable that the molecular structure of the giant cluster Au130(C≡CR)50 is revealed, which presents important information for understanding the structure of the mysterious Au130 nanoclusters. Theoretical calculations indicated Au130(C≡CR)50 has a smaller HOMO‐LUMO gap than Au130(S−C6H4−4−CH3)50. This facile and reliable synthetic approach will greatly accelerate further studies on all‐alkynyl‐protected gold nanoclusters. [ABSTRACT FROM AUTHOR]

The synthesis and isolation of alkynyl/chloride‐protected gold nanoclusters is described. Silica gel column chromatography is effective in isolating gold nanoclusters from the as‐synthesized cluster mixture to give the clusters Na[Au25L18] (Au25), [HNEt3]3[Au67L32Cl4] (Au67), [HNEt3]4[Au106L40Cl12] (Au106), L=3,5‐bis(trifluoromethyl)‐phenylacetylide. Au67 and Au106 are new clusters; the structures were determined by X‐ray single‐crystal diffraction. Au67 contains a distorted Au18 Marks decahedron shelled by an irregular Au32 and further protected with two V‐shaped Au2L3, 13 linear AuL2 staples and 4 chlorides. Au67 is the first structurally determined 34e superatomic gold nanocluster. Au106 is composed of 106 Au atoms co‐protected by alkynyls and chlorides. It has a Au79 kernel, like in Au102(p‐MBA)44. The surface structure of Au106 includes 20 linear Au‐alkynyl staples, 5 Cl‐Au‐Cl and 2 Cl‐Au motifs. These three gold nanoclusters show size‐dependent electrochemical properties. [ABSTRACT FROM AUTHOR]

Gold nanoclusters with surface open sites are crucial for practical applications in catalysis. We have developed a surface geometric mismatch strategy by using mixed ligands of different type of hindrance. When bulky phosphine Ph3P and planar dipyridyl amine (Hdpa) are simultaneously used, steric repulsion between the ligands will reduce the ligand coverage of gold clusters. A well‐defined access granted gold nanocluster [Au23(Ph3P)10(dpa)2Cl](SO3CF3)2 (Au23, dpa=dipyridylamido) has been successfully synthesized. Single crystal structural determination reveals that Au23 has eight uncoordinated gold atoms in the shape of a distorted bicapped triangular prism. The accessibility of the exposed Au atoms has been confirmed quantitatively by luminescent titration with 2‐naphthalenethiol. This cluster has excellent performance toward selective oxidation of benzyl alcohol to benzaldehyde and demonstrates excellent stability due to the protection of negatively charged multidentate ligand dpa. [ABSTRACT FROM AUTHOR]

By directly reducing alkynyl–silver precursors, we successfully obtained a large alkynyl‐protected silver nanocluster, (C7H17ClN)3[Ag112Cl6(C≡CAr)51], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core–shell structures (Ag13@Ag42@Ag48@Ag9), and four types of alkynyl–silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH2Cl2 solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters. [ABSTRACT FROM AUTHOR]

Two homoleptic alkynyl‐protected gold clusters with compositions of Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Na⋅1 and Ph4P⋅1, Ar=3,5‐bis(trifluoromethyl)phenyl) were synthesized via a direct reduction method. 1 is a magic cluster analogous to [Au25(SR)18]− in terms of electron counts and metal‐to‐ligand ratio. Single‐crystal structure analysis reveals that 1 has an identical Au13 kernel to [Au25(SR)18]−, but adopts a distinctly different arrangement of the six peripheral dimer staple motifs. The steric hindrance of alkynyl ligands is responsible for the D3 arrangement of Au25. The introduction of alkynyl also significantly changes the optical absorption features of the nanocluster as supported by DFT calculations. This magic cluster confirms that there is a similar but quite different parallel alkynyl‐protected metal cluster universe in comparison to the thiolated one. Magic clusters Na[Au25(C≡CAr)18] and (Ph4P)[Au25(C≡CAr)18] (Ar=3,5‐bis(trifluoromethyl)phenyl) exhibit novel connection between staples and the Au13 core. Steric hindrance caused by rigid ligand coordination preference accounts for the different geometric and electronic structures. [ABSTRACT FROM AUTHOR]

The syntheses and properties of two bimetallic nanoclusters [Au4Ag23(C≡CtBu)10(dppf)4Cl7](PF6)2 and [Au5Ag24(C≡CC6H4‐p‐tBu)16(dppf)4Cl4](PF6)3 are reported. The Au atoms distributed in both the cores and the surface motifs are clearly determined. The two nanoclusters show distinctly different geometric structures and electronic properties, which are attributed to the subtle changes in the surface alkynyl structures. Cluster control: Two different alloy Au4Ag23 and Au5Ag24 nanoclusters are induced by a subtle change of the groups on their alkynyl ligands (see figure). [ABSTRACT FROM AUTHOR]

The syntheses and properties of two bimetallic nanoclusters [Au4Ag23(C≡CtBu)10(dppf)4Cl7](PF6)2 and [Au5Ag24(C≡CC6H4‐p‐tBu)16(dppf)4Cl4](PF6)3 are reported. The Au atoms distributed in both the cores and the surface motifs are clearly determined. The two nanoclusters show distinctly different geometric structures and electronic properties, which are attributed to the subtle changes in the surface alkynyl structures. Cluster control: Two different alloy Au4Ag23 and Au5Ag24 nanoclusters are induced by a subtle change of the groups on their alkynyl ligands (see figure). [ABSTRACT FROM AUTHOR]

Abstract: The controlled synthesis and structure determination of a bimetallic nanocluster Au57Ag53(C≡CPh)40Br12 (Au57Ag53) is presented. The metal core has a four‐shell Au2M3@Au34@Ag51 @Au20 (M=1/3 Au+2/3 Ag) architecture. In contrast to the previously reported large nanoclusters that have highly symmetric kernel structures, the metal atoms in Au57Ag53 are arranged in an irregular manner with C1 symmetry. This cluster exhibits excellent thermal stability and is robust under oxidative or basic conditions. The silver precursors play a key role in dictating the structures of the nanoclusters, which suggests the importance of the counteranions used. [ABSTRACT FROM AUTHOR]

For the first time total structure determination of homoleptic alkynyl-protected gold nanoclusters is reported. The nanoclusters are synthesized by direct reduction of PhC≡CAu, to give Au44(PhC≡C)28 and Au36(PhC≡C)24. The Au44 and Au36 nanoclusters have fcc-type Au36 and Au28 kernels, respectively, as well as surrounding PhC≡C-Au-C2(Ph)Au-C≡CPh dimeric 'staples' and simple PhC≡C bridges. The structures of Au44(PhC≡C)28 and Au36(PhC≡C)24 are similar to Au44(SR)28 and Au36(SR)24, but the UV/Vis spectra are different. The protecting ligands influence the electronic structures of nanoclusters significantly. The synthesis of these two alkynyl-protected gold nanoclusters indicates that a series of gold nanoclusters in the general formula Au x(RC≡C) y as counterparts to Au x(SR) y can be expected. [ABSTRACT FROM AUTHOR]

For the first time total structure determination of homoleptic alkynyl-protected gold nanoclusters is reported. The nanoclusters are synthesized by direct reduction of PhC≡CAu, to give Au44(PhC≡C)28 and Au36(PhC≡C)24. The Au44 and Au36 nanoclusters have fcc-type Au36 and Au28 kernels, respectively, as well as surrounding PhC≡C-Au-C2(Ph)Au-C≡CPh dimeric 'staples' and simple PhC≡C bridges. The structures of Au44(PhC≡C)28 and Au36(PhC≡C)24 are similar to Au44(SR)28 and Au36(SR)24, but the UV/Vis spectra are different. The protecting ligands influence the electronic structures of nanoclusters significantly. The synthesis of these two alkynyl-protected gold nanoclusters indicates that a series of gold nanoclusters in the general formula Au x(RC≡C) y as counterparts to Au x(SR) y can be expected. [ABSTRACT FROM AUTHOR]

An intensely luminescent gold(I)-silver(I) cluster [(C)(AuPPhpy2)6Ag6(CF3CO2)3](BF4)5 (PPhpy2=bis(2-pyridyl)phenylphosphine) ( 3) is synthesized by the reaction of [(C)(AuPPhpy2)6Ag4](BF4)6 with AgCF3CO2. All eight faces of the octahedral C@Au6 core in 3 are capped, that is, six faces are capped by silver ions and two by tetrafluoroborates. Cluster 3 is intensely luminescent in solution with a quantum yield of 92 %. Ligation of CF3CO2− ions is vital for the construction and emission properties of 3, as confirmed by DFT calculations. BF4− ions are involved in the protecting sphere of the metal core, as evidenced by 19F NMR data. The participation of phosphines, CF3CO2−, and BF4− ions in the protection of the emissive core and the enhancement of the rigidity of the cluster result in the high emission efficiency. This is the first example of organic ligands and inorganic anions forming a rigid protecting sphere for luminescent coinage-metal clusters. [ABSTRACT FROM AUTHOR]

The Frontispiece shows two nanoclusters are induced by the change of the surface alkynyl structures. The alkynyl −C≡C−tBu gives rise to a more spherical surface shape in 1 (red background) while −C≡CC6H4‐p‐tBu to a flat shape in 2 (green backgroud). The red and green also represent their different crystal colors and different UV/Vis properties. There are also Cl (green ball) and dppf (purple ball) surrounding these structures, suggesting co‐protection by three types of ligands. For more information, see the Full Paper Y.‐M. Lin, Q.‐M. Wang et al. on page 16029 ff. [ABSTRACT FROM AUTHOR]

The Frontispiece shows two nanoclusters are induced by the change of the surface alkynyl structures. The alkynyl −C≡C−tBu gives rise to a more spherical surface shape in 1 (red background) while −C≡CC6H4‐p‐tBu to a flat shape in 2 (green backgroud). The red and green also represent their different crystal colors and different UV/Vis properties. There are also Cl (green ball) and dppf (purple ball) surrounding these structures, suggesting co‐protection by three types of ligands. For more information, see the Full Paper Y.‐M. Lin, Q.‐M. Wang et al. on page 16029 ff. [ABSTRACT FROM AUTHOR]

By directly reducing alkynyl–silver precursors, we successfully obtained a large alkynyl‐protected silver nanocluster, (C7H17ClN)3[Ag112Cl6(C≡CAr)51], which is hitherto the largest structurally characterized silver nanocluster in the alkynyl family. The cluster exhibits four concentric core–shell structures (Ag13@Ag42@Ag48@Ag9), and four types of alkynyl–silver binding modes are observed. Chloride was found to be critical for the stabilization and formation of the silver nanocluster. The release of chloride ions in situ from CH2Cl2 solvent has been confirmed by mass spectrometry. This study suggests that the combination of alkynyl and halide ligands will pave a new way for the synthesis of large silver nanoclusters. [ABSTRACT FROM AUTHOR]

Small anions play a big role in the preparation of an intensely luminescent gold(I)–silver(I) cluster. In their Communication on page 7117 ff. Q.‐M. Wang and co‐workers show that the stepwise addition of silver ions to the gold‐cluster precursor enhances the rigidity of the cluster. The emissive core is fully protected by organic ligands and inorganic anions, which results in high emission efficiency. [ABSTRACT FROM AUTHOR]